| Message ID | 1516749399-29504-5-git-send-email-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 23, 2018 at 03:16:39PM -0800, John Stultz wrote: > When using drm_hwcomposer with the hikey board, the resulting > display shows lots of tearing. > > This seems to be due to EGLcomposition not initializing > properly, potentially due to I'm guessing limitations of what > the utgard mali driver can do. I've noted that with the > HiKey960 board, this patch is *not* necessary. > > Hacking around a bit, I found that since the glworker code > isn't running properly, we never call glFinish(), which > is required to fix the tearing. > > Ideas for a better way to implement this would be greatly > appreciated! Sounds like you'll have to dig into the gl compositor to fix this. I think chances are quite good there's a better way than below. Good luck! > > Cc: Marissa Wall <marissaw@google.com> > Cc: Sean Paul <seanpaul@google.com> > Cc: Dmitry Shmidt <dimitrysh@google.com> > Cc: Robert Foss <robert.foss@collabora.com> > Cc: Matt Szczesiak <matt.szczesiak@arm.com> > Cc: Liviu Dudau <Liviu.Dudau@arm.com> > Cc: David Hanna <david.hanna11@gmail.com> > Cc: Rob Herring <rob.herring@linaro.org> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > v2: > * Simplified, focusing on the key glFinsh() call > --- > drmdisplaycompositor.cpp | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drmdisplaycompositor.cpp b/drmdisplaycompositor.cpp > index 3a20b31..eb0b77a 100644 > --- a/drmdisplaycompositor.cpp > +++ b/drmdisplaycompositor.cpp > @@ -439,6 +439,10 @@ int DrmDisplayCompositor::PrepareFrame(DrmDisplayComposition *display_comp) { > > fb.set_release_fence_fd(ret); > ret = 0; > + } else { > + /*If we're not doing anything, block to avoid tearing */ > + glFinish(); > + return 0; > } > } > > -- > 2.7.4 >
On Wed, Jan 24, 2018 at 7:26 AM, Sean Paul <seanpaul@chromium.org> wrote: > On Tue, Jan 23, 2018 at 03:16:39PM -0800, John Stultz wrote: >> When using drm_hwcomposer with the hikey board, the resulting >> display shows lots of tearing. >> >> This seems to be due to EGLcomposition not initializing >> properly, potentially due to I'm guessing limitations of what >> the utgard mali driver can do. I've noted that with the >> HiKey960 board, this patch is *not* necessary. >> >> Hacking around a bit, I found that since the glworker code >> isn't running properly, we never call glFinish(), which >> is required to fix the tearing. >> >> Ideas for a better way to implement this would be greatly >> appreciated! > > Sounds like you'll have to dig into the gl compositor to fix this. I think > chances are quite good there's a better way than below. Yes, I did spent a little bit of time earlier trying to rewrite the gl shader to try to build for the utgard level hardware, but wasn't very successful. At a deeper level I guess I'm not sure the glcompositor is useful in this case, since we're doing single plane client side compositing (as short of the glFinish bit, not running it doesn't seem to keep things from working). But I'll look into that again. Again forgive as I really a bit in the dark on most graphics details, but the other more basic question I'm a bit unsure of is, does this patch even make any functional sense? If we're not using the glcompositor and are using the atomic commit in ApplyFrame(), why the need for glFinish to avoid tearing? Is it that the we commit the frame atomically to the display, but if we don't block w/ glFinish() the gpu is still drawing into it? It seems we'd want a buffer specific fence to wait on rather then waiting for all gl calls to complete (if I'm understanding how glFinish() works). Thanks again for your review feedback! thanks -john
On Wed, Jan 24, 2018 at 1:26 PM, John Stultz <john.stultz@linaro.org> wrote: > On Wed, Jan 24, 2018 at 7:26 AM, Sean Paul <seanpaul@chromium.org> wrote: >> On Tue, Jan 23, 2018 at 03:16:39PM -0800, John Stultz wrote: >>> When using drm_hwcomposer with the hikey board, the resulting >>> display shows lots of tearing. >>> >>> This seems to be due to EGLcomposition not initializing >>> properly, potentially due to I'm guessing limitations of what >>> the utgard mali driver can do. I've noted that with the >>> HiKey960 board, this patch is *not* necessary. >>> >>> Hacking around a bit, I found that since the glworker code >>> isn't running properly, we never call glFinish(), which >>> is required to fix the tearing. >>> >>> Ideas for a better way to implement this would be greatly >>> appreciated! >> >> Sounds like you'll have to dig into the gl compositor to fix this. I think >> chances are quite good there's a better way than below. > > Yes, I did spent a little bit of time earlier trying to rewrite the gl > shader to try to build for the utgard level hardware, but wasn't very > successful. At a deeper level I guess I'm not sure the glcompositor is > useful in this case, since we're doing single plane client side > compositing (as short of the glFinish bit, not running it doesn't seem > to keep things from working). But I'll look into that again. > > Again forgive as I really a bit in the dark on most graphics details, > but the other more basic question I'm a bit unsure of is, does this > patch even make any functional sense? I'd think not. The only thing that makes me question that is I've seen glFinish calls in gralloc (framebuffer) cases. But those cases were prior to explicit fence support. > If we're not using the > glcompositor and are using the atomic commit in ApplyFrame(), why the > need for glFinish to avoid tearing? Is it that the we commit the > frame atomically to the display, but if we don't block w/ glFinish() > the gpu is still drawing into it? It seems we'd want a buffer > specific fence to wait on rather then waiting for all gl calls to > complete (if I'm understanding how glFinish() works). That seems like the right approach. Are we failing to pass fences associated with input layers to DRM? Rob
Hi John, I took your patches for a spin on Hikey960. Some findings: Even with this patch I'm getting some tearing on Hikey960, not a lot as you reported on Hikey, still there are some small black squares, less than 10 of aproximetly 20x20. So I investigated a little bit through drm_hwcomposer and found some issues, maybe they could help you somehow, see bellow: Wed, Jan 24, 2018 at 01:58:55PM -0600, Rob Herring wrote: > On Wed, Jan 24, 2018 at 1:26 PM, John Stultz <john.stultz@linaro.org> wrote: > > On Wed, Jan 24, 2018 at 7:26 AM, Sean Paul <seanpaul@chromium.org> wrote: > >> On Tue, Jan 23, 2018 at 03:16:39PM -0800, John Stultz wrote: > >>> When using drm_hwcomposer with the hikey board, the resulting > >>> display shows lots of tearing. > >>> > >>> This seems to be due to EGLcomposition not initializing > >>> properly, potentially due to I'm guessing limitations of what > >>> the utgard mali driver can do. I've noted that with the > >>> HiKey960 board, this patch is *not* necessary. > >>> > >>> Hacking around a bit, I found that since the glworker code > >>> isn't running properly, we never call glFinish(), which > >>> is required to fix the tearing. > >>> > >>> Ideas for a better way to implement this would be greatly > >>> appreciated! > >> > >> Sounds like you'll have to dig into the gl compositor to fix this. I think > >> chances are quite good there's a better way than below. > > > > Yes, I did spent a little bit of time earlier trying to rewrite the gl > > shader to try to build for the utgard level hardware, but wasn't very > > successful. At a deeper level I guess I'm not sure the glcompositor is > > useful in this case, since we're doing single plane client side > > compositing (as short of the glFinish bit, not running it doesn't seem > > to keep things from working). But I'll look into that again. > > > > Again forgive as I really a bit in the dark on most graphics details, > > but the other more basic question I'm a bit unsure of is, does this > > patch even make any functional sense? > > I'd think not. The only thing that makes me question that is I've seen > glFinish calls in gralloc (framebuffer) cases. But those cases were > prior to explicit fence support. > > > If we're not using the > > glcompositor and are using the atomic commit in ApplyFrame(), why the > > need for glFinish to avoid tearing? Is it that the we commit the > > frame atomically to the display, but if we don't block w/ glFinish() > > the gpu is still drawing into it? It seems we'd want a buffer > > specific fence to wait on rather then waiting for all gl calls to > > complete (if I'm understanding how glFinish() works). > > That seems like the right approach. Are we failing to pass fences > associated with input layers to DRM? > > Rob > _______________________________________________ It seems that we don't pass any explicit fences to the kernel for IN_FENCE_FD property. This particular line seems wrong. @@ -593,14 +594,17 @@ int DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, else rotation |= DRM_MODE_ROTATE_0; - if (fence_fd < 0) { + if (fence_fd >= 0) { Also, if you track the value of the OUT_FENCE_PTR property, it seems that it gets lost. As far I was able to track it down it seem that it should have been used by AddFenceToRetireFence, and then be passed to SurfaceFlinger through retire_fence parameter of PresentDisplay. But, that doesn't happen because AddFenceToRetireFence get's called each time on a new DrmDisplayComposition object, before calling ApplyComposition. Both of this findings should have explained the tearing, however I hacked something today and it didn't fix it for Hikey960, maybe you have more luck. Thank you, Alex Gheorghe > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
On Wed, Jan 31, 2018 at 10:51 AM, Alexandru-Cosmin Gheorghe <Alexandru-Cosmin.Gheorghe@arm.com> wrote: > Hi John, > > I took your patches for a spin on Hikey960. Some findings: > Even with this patch I'm getting some tearing on Hikey960, not a lot as you > reported on Hikey, still there are some small black squares, less than 10 of > aproximetly 20x20. Sweet! I'm glad you were able to get it up and running! I think the black squares are a separate thing, more on that below. > So I investigated a little bit through drm_hwcomposer and found some > issues, maybe they could help you somehow, see bellow: Very much appreciate the extra review and eyes on the code! >> > Yes, I did spent a little bit of time earlier trying to rewrite the gl >> > shader to try to build for the utgard level hardware, but wasn't very >> > successful. At a deeper level I guess I'm not sure the glcompositor is >> > useful in this case, since we're doing single plane client side >> > compositing (as short of the glFinish bit, not running it doesn't seem >> > to keep things from working). But I'll look into that again. >> > >> > Again forgive as I really a bit in the dark on most graphics details, >> > but the other more basic question I'm a bit unsure of is, does this >> > patch even make any functional sense? >> >> I'd think not. The only thing that makes me question that is I've seen >> glFinish calls in gralloc (framebuffer) cases. But those cases were >> prior to explicit fence support. >> >> > If we're not using the >> > glcompositor and are using the atomic commit in ApplyFrame(), why the >> > need for glFinish to avoid tearing? Is it that the we commit the >> > frame atomically to the display, but if we don't block w/ glFinish() >> > the gpu is still drawing into it? It seems we'd want a buffer >> > specific fence to wait on rather then waiting for all gl calls to >> > complete (if I'm understanding how glFinish() works). >> >> That seems like the right approach. Are we failing to pass fences >> associated with input layers to DRM? >> _______________________________________________ > It seems that we don't pass any explicit fences to the kernel for > IN_FENCE_FD property. This particular line seems wrong. > > @@ -593,14 +594,17 @@ int > DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, > else > rotation |= DRM_MODE_ROTATE_0; > > - if (fence_fd < 0) { > + if (fence_fd >= 0) { I'll give that a whirl. > Also, if you track the value of the OUT_FENCE_PTR property, it seems > that it gets lost. As far I was able to track it down it seem that > it should have been used by AddFenceToRetireFence, and then be passed to > SurfaceFlinger through retire_fence parameter of PresentDisplay. But, > that doesn't happen because AddFenceToRetireFence get's called each > time on a new DrmDisplayComposition object, before calling > ApplyComposition. I'll look into this some more as well. I've not yet gotten into the details of the fence handling in drm_hwcomposer yet, so I'll have to check that out. > Both of this findings should have explained the tearing, however I > hacked something today and it didn't fix it for Hikey960, maybe > you have more luck. The issue with the black/grey blocks is a separate problem with the 4.9 based kernels that I'm still chasing down, we see it (though less often) w/o the hwcomposer, and I think it has to do with something off in the CMA allocations. We don't see it with the 4.4 or the 4.14 based tree i'm also prepping. Thanks again for the feedback! I'm really happy to have your input here, so if you do generate any further changes, let me know and I'll try to integrate them into the patch set! thanks -john
On Wed, Jan 31, 2018 at 11:03 AM, John Stultz <john.stultz@linaro.org> wrote: > On Wed, Jan 31, 2018 at 10:51 AM, Alexandru-Cosmin Gheorghe > <Alexandru-Cosmin.Gheorghe@arm.com> wrote: >> It seems that we don't pass any explicit fences to the kernel for >> IN_FENCE_FD property. This particular line seems wrong. >> >> @@ -593,14 +594,17 @@ int >> DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, >> else >> rotation |= DRM_MODE_ROTATE_0; >> >> - if (fence_fd < 0) { >> + if (fence_fd >= 0) { > > I'll give that a whirl. So I did give that a whirl after you suggested it, but it ended up causing nothing to be displayed, and I unfortunately didn't have time right then to dig much further. Rob however re-found this issue today, and I've been digging a bit more. At least with the HiKey board, it seem the trouble is when the IN_FENCE_FD is added to the pset, the atomic commit calls start to fail. I dug in and it seems we're catching in the kernel on the if (file->f_op != &sync_file_fops) check in sync_file_fdget(). I'm now trying to trace back to where the in fence was provided from to see what might be going wrong there. Curious if this is anything you ran across in your attempts? thanks -john
On Mon, Feb 12, 2018 at 08:43:10PM -0800, John Stultz wrote: > On Wed, Jan 31, 2018 at 11:03 AM, John Stultz <john.stultz@linaro.org> wrote: > > On Wed, Jan 31, 2018 at 10:51 AM, Alexandru-Cosmin Gheorghe > > <Alexandru-Cosmin.Gheorghe@arm.com> wrote: > >> It seems that we don't pass any explicit fences to the kernel for > >> IN_FENCE_FD property. This particular line seems wrong. > >> > >> @@ -593,14 +594,17 @@ int > >> DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, > >> else > >> rotation |= DRM_MODE_ROTATE_0; > >> > >> - if (fence_fd < 0) { > >> + if (fence_fd >= 0) { > > > > I'll give that a whirl. > > So I did give that a whirl after you suggested it, but it ended up > causing nothing to be displayed, and I unfortunately didn't have time > right then to dig much further. > > Rob however re-found this issue today, and I've been digging a bit > more. At least with the HiKey board, it seem the trouble is when the > IN_FENCE_FD is added to the pset, the atomic commit calls start to > fail. I dug in and it seems we're catching in the kernel on the if > (file->f_op != &sync_file_fops) check in sync_file_fdget(). > > I'm now trying to trace back to where the in fence was provided from > to see what might be going wrong there. I would be surprised if this fence is not created by the GPU driver. But, the whole Android stack is new to me, so I might be wrong. > > Curious if this is anything you ran across in your attempts? Sorry, on Hikey960, I don't have this problem. Are you using the same 4.9 kernel from your branch(hikey-hwcomposer-deps)? > > thanks > -john Regards, Alex Gheorghe IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
On Tue, Feb 13, 2018 at 2:45 AM, Alexandru-Cosmin Gheorghe <Alexandru-Cosmin.Gheorghe@arm.com> wrote: > On Mon, Feb 12, 2018 at 08:43:10PM -0800, John Stultz wrote: >> On Wed, Jan 31, 2018 at 11:03 AM, John Stultz <john.stultz@linaro.org> wrote: >> > On Wed, Jan 31, 2018 at 10:51 AM, Alexandru-Cosmin Gheorghe >> > <Alexandru-Cosmin.Gheorghe@arm.com> wrote: >> >> It seems that we don't pass any explicit fences to the kernel for >> >> IN_FENCE_FD property. This particular line seems wrong. >> >> >> >> @@ -593,14 +594,17 @@ int >> >> DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, >> >> else >> >> rotation |= DRM_MODE_ROTATE_0; >> >> >> >> - if (fence_fd < 0) { >> >> + if (fence_fd >= 0) { >> > >> > I'll give that a whirl. >> >> So I did give that a whirl after you suggested it, but it ended up >> causing nothing to be displayed, and I unfortunately didn't have time >> right then to dig much further. >> >> Rob however re-found this issue today, and I've been digging a bit >> more. At least with the HiKey board, it seem the trouble is when the >> IN_FENCE_FD is added to the pset, the atomic commit calls start to >> fail. I dug in and it seems we're catching in the kernel on the if >> (file->f_op != &sync_file_fops) check in sync_file_fdget(). >> >> I'm now trying to trace back to where the in fence was provided from >> to see what might be going wrong there. > I would be surprised if this fence is not created by the GPU driver. > But, the whole Android stack is new to me, so I might be wrong. Yes, I went digging on this last night and it ends up the utgard driver we use (r7p0) isn't giving us a dmabuf fence, instead we're getting a mali_sync_fence. There's a newer kernel driver release (r8p1), which seems to correct this, but it also is version tied to the binary blob, which I don't have a matching update for. I spent a bit of time trying to hack out just the dmabuf fence bits, but it rarely boots all the way and frequently locks the board up, so I'm probably mucking the library driver interface in some way. Its a well known sad song. >> Curious if this is anything you ran across in your attempts? > Sorry, on Hikey960, I don't have this problem. Are you using the > same 4.9 kernel from your branch(hikey-hwcomposer-deps)? Thanks for confirming! I'll be double checking on the hikey960 soon. I suspect the bifrost driver is giving back the right structure if it was working for you. thanks -john
On Tue, Feb 13, 2018 at 2:03 PM, John Stultz <john.stultz@linaro.org> wrote: > On Tue, Feb 13, 2018 at 2:45 AM, Alexandru-Cosmin Gheorghe > <Alexandru-Cosmin.Gheorghe@arm.com> wrote: >> On Mon, Feb 12, 2018 at 08:43:10PM -0800, John Stultz wrote: >>> On Wed, Jan 31, 2018 at 11:03 AM, John Stultz <john.stultz@linaro.org> wrote: >>> > On Wed, Jan 31, 2018 at 10:51 AM, Alexandru-Cosmin Gheorghe >>> > <Alexandru-Cosmin.Gheorghe@arm.com> wrote: >>> >> It seems that we don't pass any explicit fences to the kernel for >>> >> IN_FENCE_FD property. This particular line seems wrong. >>> >> >>> >> @@ -593,14 +594,17 @@ int >>> >> DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp, >>> >> else >>> >> rotation |= DRM_MODE_ROTATE_0; >>> >> >>> >> - if (fence_fd < 0) { >>> >> + if (fence_fd >= 0) { >>> > >>> > I'll give that a whirl. >>> >>> So I did give that a whirl after you suggested it, but it ended up >>> causing nothing to be displayed, and I unfortunately didn't have time >>> right then to dig much further. >>> >>> Rob however re-found this issue today, and I've been digging a bit >>> more. At least with the HiKey board, it seem the trouble is when the >>> IN_FENCE_FD is added to the pset, the atomic commit calls start to >>> fail. I dug in and it seems we're catching in the kernel on the if >>> (file->f_op != &sync_file_fops) check in sync_file_fdget(). >>> >>> I'm now trying to trace back to where the in fence was provided from >>> to see what might be going wrong there. >> I would be surprised if this fence is not created by the GPU driver. >> But, the whole Android stack is new to me, so I might be wrong. > > Yes, I went digging on this last night and it ends up the utgard > driver we use (r7p0) isn't giving us a dmabuf fence, instead we're > getting a mali_sync_fence. > > There's a newer kernel driver release (r8p1), which seems to correct > this, but it also is version tied to the binary blob, which I don't > have a matching update for. I spent a bit of time trying to hack out > just the dmabuf fence bits, but it rarely boots all the way and > frequently locks the board up, so I'm probably mucking the library > driver interface in some way. > > Its a well known sad song. So, I took another stab at this tonight and actually got the dmabuf fence handling transplanted into the older r7p0 driver we're using. So with that and the recent fence_fd bug that has been fixed in master, things are working *much* better. No gl_finsh() hacks needed to avoid tearing and performance is improved nicely. thanks -john
diff --git a/drmdisplaycompositor.cpp b/drmdisplaycompositor.cpp index 3a20b31..eb0b77a 100644 --- a/drmdisplaycompositor.cpp +++ b/drmdisplaycompositor.cpp @@ -439,6 +439,10 @@ int DrmDisplayCompositor::PrepareFrame(DrmDisplayComposition *display_comp) { fb.set_release_fence_fd(ret); ret = 0; + } else { + /*If we're not doing anything, block to avoid tearing */ + glFinish(); + return 0; } }
When using drm_hwcomposer with the hikey board, the resulting display shows lots of tearing. This seems to be due to EGLcomposition not initializing properly, potentially due to I'm guessing limitations of what the utgard mali driver can do. I've noted that with the HiKey960 board, this patch is *not* necessary. Hacking around a bit, I found that since the glworker code isn't running properly, we never call glFinish(), which is required to fix the tearing. Ideas for a better way to implement this would be greatly appreciated! Cc: Marissa Wall <marissaw@google.com> Cc: Sean Paul <seanpaul@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Robert Foss <robert.foss@collabora.com> Cc: Matt Szczesiak <matt.szczesiak@arm.com> Cc: Liviu Dudau <Liviu.Dudau@arm.com> Cc: David Hanna <david.hanna11@gmail.com> Cc: Rob Herring <rob.herring@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> --- v2: * Simplified, focusing on the key glFinsh() call --- drmdisplaycompositor.cpp | 4 ++++ 1 file changed, 4 insertions(+)